Diodorus Siculus, Library of History 4. 7. 1 (trans. Oldfather) (Greek historian C1st B.C.) :
"Hesiod even gives their names [the Muses'] when he writes: ‘Kleio, Euterpe, and Thaleia, Melpomene, Terpsikhore and Erato, and Polymnia, Ourania, Kalliope too, of them all the most comely.’
To each of the Mousai (Muses) men assign her special aptitude for one of the branches of the liberal arts, such as poetry, song, pantomimic dancing, the round dance with music, the study of the stars, and the other liberal arts . . . For the name of each Mousa (Muse), they say, men have found a reason appropriate to her . . . Euterpe, because she gives to those who hear her sing delight (terpein) in the blessings which education bestows."